Conventional and enantioselective gas chromatography with microfabricated planar columns for analysis of real-world samples of plant volatile fraction.

Within a project exploring the application of lab-on-chip GC to in-field analysis of the plant volatile fraction, this study evaluated the performance of a set of planar columns (also known as microchannels, MEMS columns, or microfabricated columns) of different dimensions installed in a conventional GC unit. Circular double-spiral-shaped-channel planar columns with different square/rectangular sections up to 2m long were applied to the analysis of both essential oils and headspace samples of a group of medicinal and aromatic plants (chamomile, peppermint, sage, rosemary, lavender and bergamot) and of standard mixtures of related compounds; the results were compared to those obtained with reference narrow-bore columns (l:5m, dc:0.1mm, df:0.1 µm). The above essential oils and headspaces were first analyzed quali-and quantitatively with planar columns statically coated with conventional stationary phases (5%-phenyl-polymethylsiloxane and auto-bondable nitroterephthalic-acid-modified polyethylene glycol), and then submitted to chiral recognition of their diagnostic markers, by enantioselective GC with a planar columns coated with a cyclodextrin derivative (30% 6(I-VII)-O-TBDMS-3(I-VII)-O-ethyl-2(I-VII)-O-ethyl-ß-cyclodextrin in PS-086). Column characteristics and analysis conditions were first optimized to obtain suitable retention and efficiency for the samples investigated. The planar columns tested showed performances close to the reference conventional narrow-bore columns, with theoretical plate numbers per meter (N/m) ranging from 6100 to 7200 for those coated with the conventional stationary phases, and above 5600 for those with the chiral selector.

[Changes in fibrinogen values in children with acute articular rheumatism and streptococcal disease]. / Variazioni del tasso del fibrinogeno in soggetti affetti da reumatismo articolare acuto e da streptococcia nell'età pediatrica.

A study was made of changes in body fluid parameters of rheumatism following treatment with sulphoadenosine-methionine and classic forms of management. Particular attention is drawn to improvement of the serum electrophoretic picture (especially in the case of alpha 2 and gamma-globulins) with respect to untreated control group. Note is also taken of the drug's positive influence on liver function, particularly with regard to lactate hydrogenase, compared with the variations in such parameters in the control group.